1. Field of the Invention
The present invention relates to a program information transmission apparatus that transmits program information in a broadcasting system, such as a digital broadcasting system.
2. Description of the Related Art
It is planned to transmit program information as one service to viewers in a digital broadcasting system. The program information is similar to a newspaper television guide and gives information concerning broadcast programs. For instance, the program information shows the performers and summaries of the broadcast programs. The program information is repeatedly transmitted with a specific cycle to allow viewers to obtain the program information at any necessary time and to determine which broadcast program to watch by referring to the program information.
A conventional program information transmission apparatus, however, transmits program information without adjusting the transmission amount of the program information unless the bandwidth assigned to the program information is fully used. As a result, there may be cases where the program information is intensively transmitted at specific time.
FIG. 1 is an example timing chart showing program information transmission. In this drawing, long-term program information A is repeatedly transmitted with a cycle of T1 and short-term program information B is repeatedly transmitted with a cycle of T2. Also, all of the program information A is transmitted within a time period of Δt1 and all of the program information B is transmitted within a time period of Δt2. As a result, as shown in this drawing, the program information is intensively transmitted at specific time.
The processing by a reception apparatus that receives program information is next described. After receiving program information, the reception apparatus temporarily stores the received program information in a reception buffer, performs necessary processing on the program information in the reception buffer, and stores the processed program information in a memory whose capacity is larger than that of the reception buffer. If the program information is intensively transmitted at specific time as described above, there may be cases where the stated processing by the reception apparatus does not catch up with the program information transmission and an overflow will occur in the reception buffer.